The role of follicle-stimulating hormone and luteinizing hormone in ovarian stimulation Current concepts

Current practice of controlled ovarian stimulation (COS) for in vitro fertilization (IVF) has the possibility of using different protocols depending on the choice of the gonad- otrophin-releasing hormone analog (GnRHa) and the diverse gonadotropin preparations (1). With regard to the latter, a major debate continues regarding using pure follicle-stimulating hormone (FSH)-alone regimens or administering some kind of luteinizing hormone (LH) activity-containing preparations.